The National Drug Research Institute is funded by
the Australian National Drug Strategy.

International comparisons
of alcohol consumption and its consequences can serve multiple purposes. For
example, despite differences among countries in drinking cultures, drink sizes
and strengths, and methods of measuring alcohol consumption, international survey
research has provided a substantial amount of information on the rates of abstinence
or current drinking, the frequency of drinking or binge drinking, and the mean
consumption among both adults and youths in many countries. Other studies using
aggregate–level data have analyzed per capita alcohol consumption in various
countries. These studies can be used to relate per capita consumption to certain
alcohol–related outcomes and to evaluate changes of both consumption and
different outcomes within a country or across countries over time. Some problems
associated with international research, however, such as issues of comparability
of surveys, still need to be resolved.
Key words: international AODR (alcohol and other drug related) problems;
international differences; cultural patterns of drinking; research quality;
alcohol quantity–frequency methods; measure of AOD (alcohol and other
drug) volume and strength; cross–sectional study; gender differences;
AOD abstinence; aggregate–level statistical data

Researchers in numerous
countries have conducted analyses of alcohol consumption and general population
surveys to ascertain the level and consequences of alcohol use. In recent years,
investigators also have made attempts to compare drinking rates and other drinking
variables across different countries. One reason for researching across national
borders is the need for descriptive epidemiology (Room 1988). For example, national
governments often want to know how their countries measure up against others
in per capita consumption or in other comparative rankings of alcohol use. Another
reason for comparative research is the desire to further theoretical knowledge;
social scientists often employ comparative designs to develop or test theories.
In the case of alcohol research, comparisons among different countries can help
researchers determine how variations in social, cultural, political, environmental,
and genetic factors can influence drinking behavior. For example, in the case
of research on gender differences in alcohol use, international comparisons
could help distinguish which differences in men’s and women’s drinking
behavior can be attributed to biological differences and which to sociocultural
factors (Wilsnack et al. 2000).

Epidemiologic research into
the underlying mechanisms (i.e., the etiology) of any disorder generally addresses
two questions (Rose 1985):

What are the causes
of individual cases of the disorder (e.g., alcoholism)?

What factors, such
as sociocultural or political influences, contribute to the incidence of
the condition in an entire population?

The type of question to
be answered determines the level at which researchers compare data in international
research. To answer the first question, investigators would mainly use individual–level
studies (e.g., determine the level of alcohol consumption in individual drinkers
within a country) to address within–population variability. To answer
the second question, it may be more useful to conduct aggregate–level
studies that determine overall alcohol consumption in a population (e.g., per
capita consumption) to model between–population variability. Such aggregate–level
analyses are particularly useful when some societal or environmental factors
are constant or almost constant within a population. For example, Rose (1985)
notes the hypothetical example of a population in which every person smokes
20 cigarettes per day. An epidemiologist who uses individual–level data
to study risk factors for lung cancer in such a society could identify factors
that vary between people with and without the disease (e.g., genetic susceptibility)
but would not be able to identify smoking as a cause of lung cancer. Similarly,
drinking patterns may show little variability within a drinking culture; accordingly,
it may be more valuable to study the effects of various drinking patterns by
comparing drinking patterns of different cultures. For any research question,
however, both aggregate–level and individual–level studies have
advantages as well as limitations (e.g., Greenland and Robins 1994).

This article describes some
of the methodological problems involved in measuring drinking rates across countries,
such as differences in drinking cultures, drink sizes, and measurement instruments.
It then reviews the results of various types of studies that have examined drinking
rates across countries. Finally, the article discusses how such results should
be interpreted given the limitations of such studies, and it gives some recommendations
for improving comparative international alcohol epidemiology for the future.

GENERAL METHODOLOGICAL
ISSUES IN INTERNATIONAL SURVEY RESEARCH

Differences in Drinking
Cultures

Throughout the world, numerous
different drinking cultures and attitudes toward alcohol exist. A more theoretical
literature, which is somewhat separate from research comparing actual survey
rates of alcohol consumption across countries, has been devoted to describing
these differing drinking cultures. This research has had various historical
traditions (Room 1988; Room and Mäkelä 2000), the most recent of which
has focused primarily on differences between North American and European countries,
dividing them into groups with either high or low per capita alcohol consumption,
or so–called wet or dry cultures. These two categories also are commonly
associated with various correlates, such as a history of temperance movements
or a dominance of wine versus distilled spirits consumption (e.g., Peele 1997;
Levine 1992; Room 1982).

Traditionally, the wet/dry
distinction has been described as follows:

In wet cultures, alcohol
is integrated into daily life and activities (e.g., is consumed with meals)
and is widely available and accessible. In these cultures, abstinence rates
are low, and wine is largely the beverage of preference. European countries
bordering the Mediterranean have traditionally exemplified wet cultures.

In dry cultures, alcohol
consumption is not as common during everyday activities (e.g., it is less
frequently a part of meals) and access to alcohol is more restricted. Abstinence
is more common, but when drinking occurs it is more likely to result in
intoxication; moreover, wine consumption is less common. Examples of traditionally
dry cultures include the Scandinavian countries, the United States, and
Canada.

More recent comparative
research, however, has found that, especially in Europe, the previous wet/dry
division seems to be disappearing and a homogenization of consumption rates
and beverage preferences is increasingly evident. For example, both Allamani
and colleagues (2000) and Leifman (2001) have reported that wine consumption
has decreased in the traditionally wet Mediterranean countries and that overall
alcohol consumption has increased in the northern European countries. Room and
Mäkelä (2000) also have reconsidered the simple wet/dry dichotomy
and have instead proposed a new typology that considers a variety of drinking
behaviors, such as the regularity of drinking and the extent of drunkenness.
Such a typology may better fit the distinctions in drinking cultures that are
emerging today. Nevertheless, the wet/dry dichotomy has represented a scale
of extremes on which to measure drinking cultures and around which a fair amount
of past research literature has been organized.

Researchers must take differences
in drinking cultures into account when conducting international comparisons,
in order to allow for a valid measurement of alcohol consumption in any given
country. For example, in countries where drinking typically is frequent and
regular, a simple questionnaire asking how often and how much people drink (i.e.,
a quantity–frequency index) may correctly measure most of the consumption.
In countries where infrequent heavy episodic drinking occurs, however, questions
regarding occasions when higher quantities of alcohol are consumed are indispensable.
Some data collection instruments can be adjusted to the local drinking culture
to accurately measure alcohol consumption and reflect the consumption patterns.

Because of the differences
in drinking patterns, no single best instrument exists for measuring consumption.
Nevertheless, a standard instrument that is flexible enough to cover most drinking
patterns should be used in comparative research to ensure that the data obtained
from different
cultures are indeed comparable. In addition, the accuracy and comparability
across studies of alcohol consumption measurements depend on several potential
sources of measurement error. These include response rates among study participants,
the mode of survey administration (e.g., face–to–face versus telephone
interviews), and the representativeness of the sample. All of these factors
can influence estimates of drinking variables. A recent international conference
focused on developing consensus on questionnaire items for measuring alcohol
consumption and alcohol–related social harm in international comparisons.
The recommendations from this conference (Dawson and Room 2000), as well as
the recently published International Guide for Monitoring Alcohol Consumption
and Related Harm (World Health Organization [WHO] 2000), may help optimize
comparability in international alcohol surveys.

The following sections demonstrate
the complexity of assessing alcohol consumption using two examples—drink
size and strength, and measurement instruments.

Variation in Drink Sizes
and Strengths

The basic problem for researchers
conducting surveys of alcohol consumption is how to measure the amount of pure
alcohol (chemically known as ethanol) a respondent consumes, both on an individual
drinking occasion or day, and cumulatively over a longer period. All researchers
conducting surveys of alcohol consumption must make assumptions about the serving
size and alcohol content of the drinks people say they have consumed. In economically
developed countries, however, it is becoming increasingly difficult to make
such assumptions because of a bewildering array of beverages on the market that
come in containers of varying sizes and with varying strengths. For example,
in Australia at least 10,000 varieties of wine, distilled spirits, and fruit–
or beer–based drinks are available for sale.

Another factor adding to
the complexity of accurately measuring alcohol consumption is that consumption
is conventionally expressed in grams of ethanol. One cannot ask respondents
how many grams of ethanol they consume, however, because people generally do
not think about their drinking in terms of alcohol content. Instead, researchers
ask about the number of “drinks,” “units,” “bottles,”
or “cans” a person typically consumes, depending on the national
culture. These everyday units, which respondents recognize, contain varying
amounts of ethanol, even within a particular country. This problem is further
compounded by the fact that when drinks are poured from a common container (e.g.,
a bottle, cask, or can), the amounts poured will vary greatly both among “home
measures” (Lemmens 1994) and among drinks served on licensed premises
(Banwell 1999). For example, Kaskutas and Graves (2000) found that respondents
in a sample of African American women commonly poured themselves “drinks”
that contained up to six times the amount defined as a standard serving (i.e.,
12 g alcohol). Similarly, Banwell (1999) reported that the average serving for
a glass of wine in Melbourne bars was 180 mL, not 100 mL as defined both in
surveys and by health promoters in Australia.

The WHO (2000) recommends
that researchers address the issue of assumed drink sizes in order to enhance
comparability among alcohol surveys in different countries. This approach requires
that investigators in each country conduct observational studies to validate
assumptions regarding typical serving sizes for each major beverage in different
settings. Similarly, assumptions about typical drink strengths and container
sizes, which ideally would be based on official sales data across time and place,
should be validated. In addition, investigators could have respondents indicate
the number of beverage containers or the portions of bottles consumed in cases
where those measures could be more meaningful than the number of glasses.

Such local efforts to maximize
the validity of the most basic (conceptual) unit of measurement in alcohol surveys—
the “drink”—can improve the international comparability of
alcohol surveys, provided that other methodological considerations, such as
sampling methodology, are also addressed. With this approach, researchers in
different countries may have to refer to differently sized “standard drinks”
or drink containers because respondents most readily understand and report on
these concepts. At the same time, however, investigators must have a valid estimate
of the amount of ethanol present in each of these drinks or containers to ensure
comparability of the data. For example, based on this information regarding
drink size and alcohol content, four British pints of beer (16 g ethanol each),
five North American bottles of beer (12–14 g ethanol each), and six Australian
“middies” of regular beer (10 g ethanol each) would be considered
to contain approximately the same quantity of ethanol (i.e., a total of approximately
60 g ethanol).

Researchers must also scrutinize
assumptions about the usual ethanol content (the strength) of major beverages.
For example, a recent Australian study noted substantial differences in the
typical strengths of beers and distilled spirits across both time and place
in Australia during the 1990s (Catalano et al. 2001). Similar findings were
reported for wine in Canada (Single and Giesbrecht 1979). Furthermore, a study
by the Finnish Foundation for Alcohol Studies (1977) documented changes in alcohol
content as high as 6 percent for cider and 8 percent for distilled spirits in
different countries over time.

Methods for Measuring
Consumption

The most commonly used and
simplest measure of alcohol consumption is the quantity–frequency index.
With this measure, respondents estimate how often they drink and how much they
drink on a typical drinking occasion. One drawback of this approach is that
the respondents tend to ignore occasional episodes of heavy consumption, which
results in underestimates of true alcohol consumption (Gruenewald and Nephew
1994). However, if respondents are asked only about consumption on recent occasions—a
so–called recent–recall approach—rather than average consumption,
they generally report significantly higher amounts per day (see Lemmens et al.
1992).

Various examples of recent–recall
approaches exist, such as drinking diaries or survey questions focusing on very
recent alcohol consumption. These approaches appear to produce relatively high
estimates of total alcohol consumption. Because the volume of alcohol reported
in drinking surveys is normally only between 40 and 60 percent of the amounts
known to be sold in the relevant region, researchers conducting drinking surveys
generally assume that the higher the reported amounts are, the more accurately
they reflect actual drinking behavior. Knibbe and Bloomfield (2001) compared
the ability of six European national surveys to account for national levels
of consumption as determined from sales data. The French survey, which contained
only one question asking how much alcohol the respondents had consumed the day
before the survey, achieved the highest estimate. In another analysis, the Australian
Institute of Health and Welfare (Mathers et al. 1999) used a survey that inquired
about alcohol consumption only over the 3 days prior to the survey. When the
data were weighted for the day of the week, the reported consumption accounted
for over 70 percent of the per capita alcohol consumption for that year. One
plausible interpretation of these findings is that they indicate that poor recall
is a major source of underestimation of alcohol consumption. Nevertheless, recent–recall
approaches also have a major weakness in that they provide a valid picture only
of recent behavior, which may not necessarily reflect typical consumption and
may miss consumption by infrequent drinkers.

Another method for preventing
underreporting of typical alcohol consumption is to use the graduated–frequency
method. With this approach, respondents are asked to estimate how frequently
they drink different daily quantities of alcohol—for example, on how many
days per week or month they have 0, 1–2, 3–4, drinks, and so on.
When researchers compared this method with both the quantity–frequency
index and a weekly–recall method, the graduated–frequency method
resulted in the highest estimates of alcohol consumption in a general population
sample from Ontario, Canada (Rehm et al. 1999).

Several other methodological
issues also must be addressed in order to maximize the comparability of different
national alcohol surveys (WHO 2000). Although the choice of methods must reflect
the major research questions being addressed, the main policy outcomes to be
measured, and the
resources available for the study, the WHO recommends that investigators pay
attention to the following issues:

The measures should
reflect both the overall volume consumed and the patterns of drinking.

Valid local estimates
of typical units of alcohol consumption should be available.

The study should include
a reference time period that matches other measures used for harms, such
as alcohol–related workplace problems in the past 12 months.

Sampling methods should
be designed to maximize the representativeness of samples.

Whenever possible,
researchers should use multiple methods to compare consumption internationally,
using recent–recall, graduated–frequency, and per capita alcohol
consumption data from each country studied.

The WHO (2000) recommends
the graduated–frequency approach as the method of choice for most purposes;
however, investigators have experienced difficulties in setting several comparable
quantity thresholds across different countries. Given local differences in drink
sizes and strengths, it is possible that only one or two such quantity thresholds,
which should correspond to certain levels of risk of experiencing adverse alcohol
effects, are practical for use in international comparative research. The WHO
(2000) suggests that the thresholds for consumption that results in a medium
risk of acute adverse outcomes should be set at > 60 g of alcohol1
per day for men and > 40 g of alcohol per day for women. (1According
to dietary guidelines in the United States, one standard drink [e.g., 12 ounces
of beer, 5 ounces of wine, or 1.5 ounces of distilled spirits] contains approximately
12 grams of alcohol.) For consumption that results in a high risk of adverse
consequences, the thresholds should be > 100 g of alcohol per day for men
and > 60 g of alcohol per day for women.

The use of different consumption
thresholds for men and women—which are based on gender differences in
alcohol metabolism—is still controversial. One review concluded that different
thresholds are most appropriate when studying short–term and long–term
physiological effects of alcohol (Graham et al. 1998). However, according to
that review different thresholds are less important for the study of behavioral
gender differences in the effects of alcohol consumption (e.g., alcohol–related
injuries), which are moderated by the slower drinking pace frequently found
in women, than for the study of biomedical gender differences (e.g., liver disease).
Conversely, a recent case control study found marked gender differences in the
risk of alcohol–related injury at different thresholds of consumption.
In that study, women at all levels of alcohol consumption had a substantially
greater risk of injury than men (Stockwell et al. 2002).

INTERNATIONAL SURVEY RESEARCH

Numerous investigators have
conducted studies of alcohol consumption among adults and youth in a number
of countries. Such consumption data collected at the individual level (i.e.,
through interviews and questionnaires) have several advantages over aggregate–level
data based on alcohol sales statistics. For example, individual–level
studies can gather information on drinking patterns, such as average consumption,
frequency of consumption, and other variables, such as heavy episodic drinking.
Moreover, these studies allow for comparisons among subgroups in the population
(e.g., based on age, gender, and ethnicity), which are not possible with per
capita consumption data based on sales. The following sections review findings
obtained in international surveys conducted among adults and youths.

Surveys of Adults

Several international comparisons
of drinking rates in adults based on general population surveys have been conducted
in the last decade or so. The studies presented here meet the following criteria:
(1) They are recent cross–sectional general population surveys. (2) They
reported prevalence rates of drinking behaviors, such as rates of abstinence
or current drinking (i.e., alcohol consumption in the past 12 months) and rates
of heavy drinking, as well as mean alcohol consumption and mean frequency of
drinking. Studies measuring alcohol dependence or alcohol problems are not discussed
here. A comprehensive review of the literature to identify such studies was
beyond the scope of this article. Rather, the authors chose studies they were
familiar with and supplemented this information with the studies’ own
literature and a confirmatory search of the Alcohol and Alcohol Problems Science
Database (ETOH), which is maintained by the National Institute on Alcohol Abuse
and Alcoholism (NIAAA), using such search terms as “international comparisons”
and “cross–cultural comparisons.” Although this list of studies
may not be exhaustive, it provides a general picture of the state of recent
comparative alcohol epidemiology.

The studies reviewed here
tend to represent bounded comparisons—that is, comparisons among several
rather similar countries (Room 1988). Only two of the studies (Wilsnack et al.
2000; Fillmore et al. 1991) sought to include a wider array of countries from
various regions (e.g., North America, Australia, the Middle East, and Europe).
The other studies primarily included groups of member states of the European
Union (EU) or Scandinavian countries. This selection reflects the present major
funding bodies for such research, such as the EU. In addition, although such
a selection may appear limited, a focus on relatively similar countries may
improve the comparability of the data. Despite considerable variation in drinking
cultures and research approaches, European countries tend to have more in common
in these respects than do, for example, African and European countries (Room
1988).

With most of these studies,
questionnaires (including discrepancies in translations) and response rates
varied to such an extent that the resulting measurement and nonresponse bias
discourage direct comparison of consumption levels (e.g., Simpura et al. in
press; Knibbe and Bloomfield 2001). Thus, most studies also included other measures
(e.g., gender ratios) to examine trends and relationships between drinking and
other variables when comparing data across countries.

Abstinence. Several
studies compared abstinence rates among adults in various countries. The countries
included in the different studies vary, making an overall analysis difficult.
The studies found the following results (see table
1):

In investigating gender
differences in drinking, the International Research Group on Gender and
Alcohol conducted a comparison among men and women in 10 countries (Wilsnack
et al. 2000). Using comparable measures constructed from the data sets collected
in the study countries, the group found that lifetime abstention for both
men and women was highest in Israel (ages 18–40 years) and lowest
in the Czech Republic.

Hupkens and colleagues
(1993) analyzed data on beverage–specific drinking frequency from
the Eurobarometer, an annual survey conducted in the EU to monitor the attitudes
of the population toward the EU and its policies. The study reported that
among the 12 EU member states in 1988, Ireland had the highest rate of abstinence
(timeframe not specified) and Denmark had the lowest rate.

In examining trends
in alcohol use across as many as 15 European countries, Simpura and Karlsson
(2001) reported rates of abstinence (definitions vary) for 1995. Among women,
the rate of abstention was highest in Portugal and lowest in Denmark. Among
men, the abstention rate was highest in Italy and lowest in Denmark.

In a study examining
episodic heavy drinking with a common questionnaire in four Scandinavian
countries, Mäkelä and colleagues (2001) found that Sweden had
the highest 12–month abstinence rate for men, Norway had the highest
rate for women, and Denmark had the lowest rate for both genders.

A recent EU project,
funded partially by the European Commission, conducted a survey of alcohol
use, alcohol–related problems, and attitudes toward alcohol in six
European countries (Leifman 2002). Surprisingly, among these countries,
abstinence in the last 12 months was lowest in Finland. Equally surprising,
the highest rate of abstinence was found in France.

Overall, these studies indicate
that in recent years the Mediterranean countries had comparatively higher rates
of abstention than countries of central Europe. Furthermore, the abstinence
rates in Scandinavian countries appear to be declining. Finally, Denmark appears
as a special case in both Scandinavian and EU–wide comparisons as a country
with low abstinence rates. These findings agree with the recently observed trend
toward a homogenization of European drinking styles.

Current Drinking.
Two studies have looked at current drinking rather than abstinence in measuring
the respondents’ drinking status. One study compared drinking patterns
between Germany and the United States. This analysis found that within a comparable
age range and with fairly similar instruments, Germany had one–third more
current drinkers (i.e., people who had consumed alcohol in the past 12 months)
than did the United States (Bloomfield et al. 2002). The other study was part
of an EU concerted action that examined women’s alcohol consumption and
alcohol problems (as well as gender differences in drinking patterns) in nine
European countries through a secondary analysis of survey data. In one of its
analyses of basic drinking measures, Ahlström and colleagues (2001) found
that current drinking rates (i.e., consumption in the last 12 months) were highest
among French men and Swedish women and were lowest among Italian men and women.
These findings for current drinking (which is the inverse of abstinence) appear
to fit the conclusions drawn regarding abstinence rates as described in the
preceding section.

Frequency of Drinking.
Another aspect of drinking behavior often measured in comparative studies is
the frequency of drinking. Several studies have assessed this variable in international
comparisons. These analyses, which included information from current drinkers
only, had the following results:

The study by Hupkens
and colleagues (1993) involving 12 EU member states found that Spain had
the highest frequency of drinking for men, Italy had the highest frequency
for women, and Ireland had the lowest frequency for both genders (in general
frequency categories2). (2General frequency categories
do not measure the actual number of days when alcohol consumption occurs
but provide more general categories, such as “every day or almost
every day,” “3 to 4 days per week,” or “never.”)

Ahlström and colleagues
(2001) determined that among nine European countries, France had the highest
and Finland had the lowest frequency of drinking (i.e., number of drinking
occasions within a month).

Wilsnack and colleagues
(2000), with their sample of 10 countries, found the highest frequencies
of drinking (i.e., number of drinking occasions in a month) among Dutch
women and Czech men and the lowest frequencies among Estonian women and
men.

Two studies examined the
rates of daily drinking in various countries. Leifman (2002) reported that when
all respondents (i.e., drinkers and nondrinkers) were included in the analysis,
Italy had the highest and Finland the lowest rates of daily drinking. Simpura
and Karlsson (2001) examined seven countries regarding daily drinking; this
analysis noted that wine countries had the highest rates, followed by beer–drinking
countries and former spirits–consuming countries. This order was true
for both men and women. Finally, in the two–country comparison of Bloomfield
and colleagues (2002), respondents (i.e., drinkers and nondrinkers) in Germany
reported almost twice as many drinking days as did U.S. respondents. All of
these studies suggest that the main wine–consuming (and wine–producing)
countries of Europe have the highest frequencies of drinking.

The international Collaborative
Alcohol–Related Longitudinal Project (e.g., Fillmore et al. 1991) conducted
meta–analyses on 39 longitudinal data sets3 on alcohol consumption
from 15 countries. Its goal was not necessarily to examine differences in basic
drinking rates across countries, but to examine and predict drinking patterns
and problems over the life course (Fillmore et al. 1991). (3In meta–analyses,
data are pooled from several studies to allow researchers to draw overall conclusions.
Longitudinal studies follow the same respondents over an extended period of
time (e.g., several years).) In one of its analyses examining the frequency
of drinking, the study took into account national origin of the data sets. It
grouped the studies into regions, including the United States, Canada (including
New Zealand), Europe, and the United Kingdom (including Ireland). This comparison
found that in relation to the United States (which was used as a reference),
the frequency of consumption was highest in the United Kingdom, followed by
the European countries and Canada (Johnstone et al. 1996).

Binge Drinking.
Binge drinking (sometimes called heavy episodic drinking) has been included
as a measure in some recent comparative studies:

Wilsnack and colleagues
(2000), in an analysis that included 10 countries, found that Canadian men
and Swedish women had the highest percentages of drinkers who had engaged
in heavy episodic drinking (the definitions of this term varied among the
countries) in the last 12 months. Conversely, Israeli men and women had
the lowest percentages of heavy episodic drinking. (This analysis included
current drinkers only.)

Studying data from
four Scandinavian countries, and considering data from all respondents (drinkers
and nondrinkers), Mäkelä and colleagues (2001) found that Danish
men and women had the highest annual frequencies of consuming six or more
drinks on one occasion, and Norwegian men and Finnish women had the lowest
frequencies.

In his study of six
EU member states, Leifman (2002) reported that when both drinkers and nondrinkers
were included in the analysis, people in the United Kingdom had the highest
annual frequency of heavy drinking (defined as drinking a bottle of wine
or the equivalent on one occasion), and people in France had the lowest.

In a comparison between
the United States and Germany including all respondents (Bloomfield et al.
2002), the number of days per month on which five or more drinks were consumed
was almost twice as high in Germany as in the United States.

No consistent pattern in
binge drinking rates emerges from these studies. This lack of consistency might
be partially attributable to the small number of studies and the varying definitions
of the behavior.

Mean Alcohol Consumption.
Several recent international studies also have compared mean levels of alcohol
consumption. In the study by Ahlström and colleagues (2001), Italian respondents
reported the highest mean monthly consumption and Finnish respondents the lowest,
when drinkers only were considered. Leifman (2002), who included all respondents
in the analysis, found the highest mean annual alcohol consumption in the United
Kingdom and the lowest consumption in Sweden. Mäkelä and colleagues
(2001) reported that among the Scandinavian countries, Denmark had the highest
and Norway had the lowest annual consumption in an analysis of all respondents.
In the study comparing the United States and Germany (Bloomfield et al. 2002),
mean monthly alcohol consumption among all respondents was more than twice as
high among German respondents as among U.S. respondents. Finally, a somewhat
older study examined differences in the sociodemographic correlates of drinking
patterns in the general populations of Switzerland, Germany, and the Netherlands
(Knibbe and Lemmens 1987). This study, which analyzed all respondents, found
that Germans had the highest average weekly consumption in terms of standard
glasses, followed by the Swiss and Dutch respondents.

As with binge drinking,
these findings do not indicate a clear pattern in mean consumption among the
countries studied. This lack of consistency could be accounted for by the varying
methods of measurement used across the studies.

Summary. Overall,
the studies reviewed in this section suggest that relatively consistent patterns
appear to exist across the reported studies with respect to abstinence and frequency
of drinking (e.g., relatively high abstinence rates in the Mediterranean countries
and highest frequency of consumption in the wine–producing countries of
Europe). Measures of binge drinking and mean consumption levels, however, exhibited
less consistency. It is difficult to determine whether these inconsistencies
stem from methodological problems or from real changes in drinking behaviors,
which no longer fit the traditional typologies of drinking cultures (e.g., the
wet/dry dichotomy). Such questions deserve increased attention as researchers
develop methodology and concepts of future studies.

Surveys of Youth

To date, researchers have
conducted two large–scale international youth surveys relating to alcohol
use, the Health Behavior of School–Aged Children (HBSC) survey and the
European School Survey Project on Alcohol and Drugs (ESPAD). The HBSC, conducted
for the fourth time in 1997–1998, included children ages 11, 13, and 15
in 26 European countries, Canada, and the United States (Currie et al. 2000).
The ESPAD surveyed 15–year–olds from 30 European countries for the
second time in 1999 (Hibell et al. 2000). The main advantage of both surveys
is the use of a common methodology in all participating countries. For example,
investigators in the participating countries of each survey used a common questionnaire,
employed a standardized sampling methodology to ensure that their samples were
representative of that country, surveyed the same age group(s) across countries,
and collected their data in the same year. Moreover, both projects required
minimum sample sizes as criteria for participation in the respective collaborative
study, guaranteeing a certain statistical power, and thus precision, of the
results. Finally, the surveys were conducted in school, a procedure that reduces
nonresponse because usually only those students who are absent on the day of
the survey do not participate (although responding to the questionnaire is voluntary).
Thus, the response rates usually exceeded 85 percent. The data presented here
refer to the most recent versions of both surveys.

Abstention Rates.
The HBSC found that in all countries abstention from alcohol covaried highly
between the sexes—that is, if the abstention rate was high among males,
it usually was also high among females. In addition, the countries maintained
their relative positions in abstention rates in all age groups tested. However,
the differences among countries in abstention rates diminished among older students.
The HBSC findings also suggested that with regard to abstention rates, the distinction
between dry or wet drinking cultures either did not apply to adolescents or
developed later in life. Thus, the HBSC found high abstention rates in prototypical
wet countries, such as France and Switzerland, but also in Norway, the United
States, and Israel. Conversely, in Denmark, Scotland, Wales, England, the Czech
Republic, and Slovakia, abstention was uncommon even at age 13.

Weekly Drinking.
The HBSC survey also provided data on the percentages of respondents who consume
alcohol at least once a week. Because these percentages included the abstainers,
the authors of this article recalculated the percentages of weekly drinkers
relative to the percentages of drinkers to determine the proportion of weekly
drinkers among all drinkers in each country. In general, these analyses demonstrate
that as the percentage of drinkers increased, so did the percentage of weekly
drinkers (r = 0.4).4 (4Israel was an exception to this
general observation.) However, one group of countries diverged from this pattern
by recording, among both males and females, high percentages of drinkers but
low percentages of weekly drinkers. This group—which consisted of Poland,
Lithuania, Estonia, Latvia, Finland, and Sweden—was the only group of
geographically connected countries exhibiting a pattern that deviated from the
patterns in other countries.

Countries with relatively
low percentages of both drinkers and weekly drinkers included Norway, Switzerland,
and the United States. Conversely, high percentages of both drinkers and weekly
drinkers were found in England, Wales, Scotland, Denmark, and Greece. Again,
no marked gender differences existed across the countries—if the percentage
of male weekly drinkers was high, so was the percentage among females. Finally,
the ranking of the countries with respect to weekly drinking remained stable
among the different age groups tested, similar to what had been observed for
the abstention rates. These findings in young people again did not seem to fit
the prototypical wet/dry classification of adult drinking in that nations with
high alcohol consumption among youth included both a wine country, Greece, and
beer–drinking countries, such as Denmark, England, and Wales.

Drinking Patterns.
The ESPAD survey, which included some countries not participating in the HBSC,
allowed for more detailed analyses of drinking patterns. To this end, the authors
of this article used the following variables from the 1999 ESPAD report (Hibell
et al. 2000):

Frequency of consuming
different types of alcoholic beverages

Alcohol consumption
three times or more in the past 30 days

“Binge”
drinking (i.e., consumption of five or more drinks in a row) three times
or more during the last 30 days

Frequency of any alcohol
consumption in the past 12 months, with abstinence defined as no alcohol
consumption in the past 12 months

Amount consumed on
the last drinking occasion.

These drinking variables
were adjusted relative to the percentage of past–year drinkers. Malta
was excluded from the analysis as a country that was different from all others
and produced extreme values.

The analyses indicate that
beer was clearly the dominant beverage of choice among the 15–year–olds
in this sample of countries (see table 2).
With the exception of one country—Hungary—the percentages of beer
drinkers outnumbered the percentages of wine drinkers. Similarly, beer drinkers
outnumbered drinkers of distilled spirits in all but three countries (i.e.,
Hungary, Norway, and Portugal). Moreover, initial findings indicated that when
beer drinking was common, so was consumption of distilled spirits. In fact,
distilled spirits, rather than wine, were the second most common beverage of
choice. Thus, only in Estonia, Italy, Latvia, Lithuania, and Romania did more
students drink wine (at least three times or more during the past 30 days) than
distilled spirits. Overall, wine consumption was not correlated with consumption
of beer or distilled spirits in young people, and high wine consumption did
not generally indicate a distinct “drinking culture.”

The percentages of binge
drinkers also varied significantly across countries (see table 2). The lowest
percentages of binge drinkers—approximately 10 percent of all drinkers—were
found in Lithuania, Greece, Slovak Republic, Portugal, and Romania. Conversely,
in Poland, Ireland, the United Kingdom, and many northern countries, the percentages
of students bingeing at least three times per month ranged between 20 and 40
percent. Bingeing, however, showed no significant association with the percentage
of drinkers in a given country. Low–bingeing countries had both high (Portugal,
Romania) and low (Greece, Slovak Republic) percentages of abstainers. Similarly,
in high–bingeing countries, both low (United Kingdom) and high (Iceland)
percentages of abstainers were found. A similar picture emerged with regard
to frequency of drinking. Overall, the wet/dry dichotomy was not evident among
young people. Although some countries exhibited such prototypical drinking behaviors,
the overall picture of drinking among young people was highly diverse.

AGGREGATE–LEVEL STUDIES
AND PER CAPITA CONSUMPTION

Some cross–national
comparisons of alcohol consumption use aggregate–level data. The most
widely analyzed variable in such studies is per capita alcohol consumption—the
amount of ethanol in liters per year that every adult consumes. To calculate
annual adult per capita consumption, one sums up production and imports of alcoholic
beverages, subtracts exports of alcoholic beverages, and then divides by the
number of adults (often all people age 15 and older) in the population. Ideally,
the calculation would also consider informal alcohol production, consumption
by residents outside the country, duty–free consumption, consumption by
foreign tourists in the country, imported alcohol re–exported to other
countries, and any additional stocks5 (WHO 2000); however, these
data are difficult to obtain. (5These additional stocks refer to
alcoholic beverages stored because they require aging [e.g., whiskey and cognac].
Thus, these beverages may have been produced in earlier years but are released
for sale or export only after reaching maturation. However, the effect of stockpiling
on estimates of total alcohol consumption in most countries is likely to be
small.)

Studies comparing per capita
consumption may have advantages over studies comparing individual–level
data, especially for cross–country comparisons. For example, aggregate
data can easily (and inexpensively) be obtained for many countries. Furthermore,
data often are available for several years, permitting the comparison of trends.
In addition, per capita consumption data may paint a more accurate picture of
overall consumption levels than surveys, which commonly result in lower estimates
of the total consumption by a population.6 (6Besides the
previously mentioned problems of under–reporting of respondents, these
lower consumption estimates may also be attributable to a disproportionate underrepresentation
of certain groups of heavier drinkers in typical samples, such as institutionalized
or homeless people.) Finally, because alcohol consumption also harms people
other than the drinkers themselves (see the article in this issue by Gmel and
Rehm), aggregate–level data may better capture the relationship between
aggregate alcohol–related consequences and changes in the drinking patterns
in a population (Norström and Skog 2001).

Aggregate–level data
also have some drawbacks, however. For example, studies usually do not report
age– and sex–specific consumption rates or the prevalence of certain
drinking patterns. However, the same per capita consumption may, in theory,
have a completely different impact on consequences, depending on factors such
as the percentage of abstainers or typical consumption patterns (e.g., more
regular, moderate consumption versus infrequent but heavy drinking).

Another possible limitation
of aggregate–level studies of associations is that these analyses are
prone to biases (often known as ecologic bias) that are unique for such types
of investigations and are not found in individual–level studies (Morgenstern
1998).7 (7A famous example of ecologic bias was reported
by Durkheim [1951{1897}], who studied suicide rates in four regions of Prussia
and found that these rates increased with the proportion of Protestants in those
regions. The aggregate–level data indicated that suicide rates among Protestants
were nearly eight times greater than among non–Protestants. Individual–level
analyses, however, demonstrated that many suicides were committed by non–Protestants,
possibly because living as a religious minority increases suicide risk. Accordingly,
more non–Protestants might take their lives (and thus increase suicide
rates) in regions with higher proportions of Protestants. Thus, the Protestant
area would have a contextual effect on non–Protestant suicides.)

Furthermore, the recording
of per capita data depends on so many factors that their use as a standard for
individual–level data is questionable. Sources of error may include illegal
production, cross–border imports, consumption by tourists, and changes
in the age composition of a country over time (for more information on these
factors, see the special issue of Contemporary Drug Problems, Vol.
27, No. 2; Summer 2000).

Despite these limitations,
aggregate–level studies can complement individual–level studies.
Thus, the combination of several data sources (e.g., aggregate–level studies,
cross–sectional and longitudinal individual studies, and laboratory studies)
may strengthen the establishment of potential causal associations (see Pernanen
2001). This strengthening effect may be even stronger if the evidence comes
from different data sources rather than from repeated analyses of the same data
source (Norström and Skog 2001).

Cross–cultural comparisons
of per capita consumption can be used in two major ways. First, investigators
can compare per capita consumption with certain alcohol–related outcomes
at a given point in time or as an average over a range of time points. For example,
in a study involving 14 European countries, Ramstedt (2001b) demonstrated
that age–adjusted mortality rates for liver cirrhosis in both men and
women increased with increasing per capita consumption. Thus, although per capita
consumption was available only for the population as a whole, this variable
correlated well with sex–specific rates of cirrhosis mortality. Similar
ecological analyses can be conducted with aggregated statistics from survey
data—for example, to link mean consumption with the proportion of heavy
drinkers or alcohol–related consequences in a population (e.g., Colhoun
et al. 1997).

Second, aggregate per capita
consumption data can be used to compare changes of both consumption and different
outcomes (e.g., cirrhosis mortality, all–cause mortality, and traffic
injuries) within a country or across countries over time. Analyzing changes
in consumption or outcomes by using time series (i.e., using a differencing
approach) instead of the original values is believed to reduce confounding and
therefore spurious associations (Norström and Skog 2001).

One of the largest studies
using this approach in recent years was the European Comparative Alcohol Study
(ECAS) (Norström 2001a). This study was conducted in 14 EU countries,
including traditional wine–drinking countries in southern Europe (e.g.,
Spain and France), beer–drinking countries in central Europe (e.g., the
United Kingdom, Ireland, and West Germany), and former spirits–drinking
countries in northern Europe (e.g., Sweden, Norway, and Finland). Among its
analyses, the ECAS compared per capita consumption and several outcomes in the
participating countries. For some outcomes, the ECAS established the same association
with alcohol consumption that was found in individual–level studies (e.g.,
unintentional injuries, such as accidental falls). Surprisingly, many of the
associations were stronger in northern countries that have lower overall alcohol
consumption than in southern countries, which generally have higher alcohol
consumption. These observations indicate the importance of different patterns
of alcohol consumption. For example, it is commonly assumed that although alcohol
consumption is lower in the northern countries, the drinking patterns are different
(e.g., people more commonly drink to intoxication and the level of distilled
spirits consumption is higher).

The relevance of drinking
patterns is supported by a recent study by Gmel and colleagues (2001), who modeled
the effects of changes in aggregate consumption on mortality across countries
using indicators of drinking patterns (e.g., drinking with meals, frequency
of drinking, drinking to intoxication, percentage of abstainers).8
(8This study was part of a series of analyses of alcohol–related
consequences within the framework of the Comparative Risk Assessment [CRA] of
the Global Burden of Disease 2000 [study, which aims to estimate the burden
stemming from alcohol consumption on a worldwide scale, including developing
countries [Rehm et al. in press]]. It was a pooled cross–sectional time
series analysis. Pooling of data is particularly important in developing countries
for which data often are available only for a few time points.) The study showed
that the more detrimental the general pattern of drinking in a country, the
higher the impact of a change in alcohol consumption on all–cause mortality.
This finding confirms that in addition to volume of drinking, patterns of drinking
have independent effects on mortality.

By widening the spectrum
of comparative research to include developing countries, researchers can enhance
understanding of the cultural impact on alcohol and related consequences because
the cultural differences in alcohol consumption are more variable on a worldwide
scale than within one or two continents. The WHO Global Alcohol Database, which
includes consumption estimates for 181 countries, is currently the most comprehensive
source of per capita consumption data. However, for some countries, the information
on per capita consumption originates from competing sources and is based on
either sales figures or production data. The accuracy of sales data generally
depends on the accuracy of export and import data (WHO 1999). The most comprehensive
source of information included in the Global Alcohol Database is a data set
published by the Food and Agriculture Organization (FAO) of the United Nations.
It provides estimates of per capita consumption based on production data and
includes not only beer, wine, and distilled spirits but also several other beverage
categories, such as palm wine; maize, millet and sorghum beer; fruit wine; rice
wine; rice–fermented beverages; cider; grape must (i.e., pressed but unfermented
grape juice); vermouth; and wheat–fermented beverages. These beverage
categories are particularly important in many developing countries.

The second main source of
data included in the Global Alcohol Database, World Drink Trends (WDT) of the
Dutch Distiller’s Association, is provided by the alcohol industry and
is based mostly on sales and tax statistics (Productschap voor Gedistilleerde
Dranken 2000). Although the WDT is assumed to provide more accurate data than
the FAO data set, it included only 58 countries in 2000. It should be noted
that the choice of data source may affect comparative research because the correlation
between FAO and WDT estimates is not perfect (r = 0.74 for those 45
countries in the WHO Global Alcohol Database for which data are available from
both sources).

Because of the limitations
of the data sets and discrepancies between them, all per capita consumption
data should be carefully checked over time both within a country and across
countries before one can draw any conclusion from comparative research that
uses data from different sources. However, an analysis of changes between time
points instead of original data (i.e., use of a differencing approach for time
series data) might be one possibility to reduce problems of comparative time
series research (although differenced time series models also have potential
pitfalls [e.g., see Rehm and Gmel 2001]). If possible, findings from aggregate–level
analyses should be corroborated with findings from individual–level analyses.
The ECAS (Norström 2001b) or the work within the Comparative Risk
Assessment (Rehm et al. in press) are promising examples of such verification.

The comparability of analyses
of per capita consumption may be affected by more than the use of different
data sources, however. For example, Ramstedt (2001a) demonstrated that
time series analyses—even within limited geographical regions, such as
Europe—might be biased by changes in the way alcohol–related outcomes
are diagnosed and recorded (e.g., because of revisions of the diagnostic manuals,
such as the WHO’s International Classification of Diseases9).
(9The International Classification of Diseases, published
by the WHO, provides diagnostic criteria for all medical conditions and allows
the classification of those conditions.) There is also evidence that alcohol–related
diseases (e.g., liver cirrhosis) may not be labeled as such in some countries,
possibly to avoid stigmatization or financial penalties to the patients and
their families (Cipriani et al. 2001).

RECOMMENDATIONS FOR FUTURE
RESEARCH

Comparing alcohol consumption
and drinking patterns internationally is not an easy task. This review has discussed
various sources of methodological problems that make such comparisons so difficult,
and the comparative research presented here reveals that the results of existing
studies are only partly consistent. Consequently, the question arises as to
how researchers can best conduct comparative alcohol research in the future.
This section presents some suggestions for possible new directions.

An obvious problem, which
in theory could easily be solved, is to maximize the comparability of surveys
by standardizing sample selection, survey protocols, response rates, modes of
survey administration, and sociodemographic factors (e.g., the age range) of
study samples. In practice, however, standardization is difficult because studies
have differing funding and priority levels across countries.

A related issue is the problem
of measuring alcohol consumption. There is an inherent conflict between efforts
to improve comparability (through standardization) and efforts to improve validity
(through use of measures best suited to a country’s drinking culture and
typical drink sizes). Some possible solutions to this issue include the following.
First, future comparative research could incorporate methodological studies
using a split sample design. With such a design, all participating countries
could use a common instrument deemed to be the best available measure of the
widest range of drinking behaviors. Simultaneously, in a small random subset,
each country could apply the instrument that is assumed to be best for that
country. Such a design would allow researchers both to compare countries with
the same measurement instrument and to explore whether using the “best”
instrument for each country would alter the conclusions.

Second, investigators could
focus on associations between drinking measures and drinking–related problems
rather than on comparisons of rates of several drinking variables. Studies found
that different epidemiological measurement instruments of alcohol consumption
commonly result in comparable relative positions of drinkers (e.g., Feunekes
et al. 1999; Rehm et al. 1999). For example, a person who is considered one
of the heaviest drinkers in a population using one instrument also will be considered
one of the heaviest drinkers using other instruments. If researchers can identify
stable associations among differing consumption measures and outcomes, they
could conduct comparative research of such associations, regardless of the instrument
used to measure alcohol consumption.

Third, investigators could
combine findings from comparative research using different types of designs
(e.g., general population surveys and aggregate–level studies) to substantiate
differences among countries.

For quantitative alcohol
epidemiology, survey designs should provide valid as well as reliable quantitative
assessments of alcohol consumption and its consequences. Therefore, investigators
should make greater efforts to ensure that assumptions about the alcohol content
of “drinks” in different countries are locally valid and should
pay attention to sampling and questionnaire–design issues. To determine
the success of such efforts researchers should compare survey results to actual
alcohol consumption when consumption can be reliably estimated from sales, taxation,
import, export, or production data (WHO 2000). The validity of comparisons of
consumption rates across regions or time periods will always be limited if the
survey results account for only a low (or varying) proportion of actual alcohol
consumption.

Most of the comparative
research to date has focused on established market economies (i.e., developed
countries). With these studies, differences in findings may partly reflect simple
“noise” as these countries are rather similar to one another compared
with developing countries. By widening the range of participating countries,
researchers may enhance knowledge about the effects of drinking patterns. Such
work is currently under way in different developing countries (Demers et al.
2001).

In conclusion, researchers
should consider the following when creating an agenda for future research. First,
investigators need to tackle more directly the major barriers to valid cross–cultural
research on drinking, using and improving on previous attempts to address the
major methodological hurdles both for comparative monitoring purposes and for
social and epidemiological investigation. The ECAS, which combines aggregate–level
findings with general population surveys using a comparable methodology, is
currently the best example of such efforts. In general, the greater the geographical,
cultural, and economic diversity among participating countries, the greater
the methodological difficulties. Comparisons within Europe will be more valid
than, for example, comparisons between urban European areas and rural Africa.
One example of an attempt to conduct valid comparisons of diverse countries
is a project called GENACIS (Gender, Alcohol and Culture: An International Study),
a multinational study funded by various sources including the U.S. National
Institute on Alcohol Abuse and Alcoholism, the European Commission, and WHO.10
(10In addition, many national governments are financing their countries’
respective research contributions.) The study, which currently involves 26 countries,
is investigating gender differences in alcohol use and consequences on a cross–cultural
level. The study includes such diverse countries as Mexico, Argentina, Sri Lanka,
Kazakhstan, France, Austria, Israel, Hungary, and Japan as well as the United
States. It employs a standardized questionnaire in as many countries as possible
and has suggested guidelines for sampling and survey methods for incoming project
partners.

Second, future international
comparative research should develop criteria for considering the validity of
comparisons of both aggregate–level and individual data. Studies also
should consider and combine data across different sources in order to strengthen
comparative analysis under less than optimal conditions. Using such approaches,
a primary task would be to determine how different drinking patterns are related
to outcomes (e.g., mortality and morbidity) and whether such differences indicate
drinking patterns that are less harmful than others. Another task would be to
identify effective measures taken in various countries to prevent negative alcohol–related
consequences. This type of research involves not only cross–sectional
studies in each study country, but also the implementation of longitudinal designs.
Current international research, however, has remained at the stage of attempting
to compare drinking rates and improve the needed methodology and therefore has
not yet reached the stage of addressing these more applied issues.

Finally, future international
comparative research should continue to fulfill a concrete public health–related
purpose through national and international monitoring activities that serve
policy and political purposes for countries and international bodies. Additionally,
international research should continue to test theories regarding political,
economic, cultural, and biological differences in alcohol use and its consequences
across countries. For example, the GENACIS project examines the influence of
biology and culture on gender differences in alcohol use and its consequences.
In addition, a recent study of per capita alcohol consumption and liver cirrhosis
mortality in 14 European countries suggested that the strength of the relationship
between drinking level and mortality may vary by regional drinking pattern and
may not be as dependent on total consumption level as previously thought (Ramstedt
2001b). This finding could be the motivation for more detailed analyses. Thus,
numerous possibilities exist for further international comparative studies that
could promote the methodological development of this research area.

ACKNOWLEDGMENTS

The authors express their
appreciation to Ms. Elisabeth Grisel–Staub for her expertise in formatting
the manuscript and to Ms. Stephanie Kramer for her stylistic improvements to
the text. Furthermore, the authors are grateful to the two anonymous reviewers
for their comprehensive and constructive suggestions.

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